Year Percent 2000 99.82479 2001 99.8124 2002 99.8 2003 99.7876 2004 99.77521 2005 99.76281 2006 99.75041 2007 99.73801 2008 99.72562 2009 99.71322 2010 99.70082 2011 99.68842 2012 99.67603 2013 99.66363 2014 99.65123 2015 99.65123